We propose to continue and expand an ongoing multicenter study designed to evaluate the reliability and validity of a brief battery of neuropsychologic tests for use in assessing patients with Alzheimer's disease (AD), This brief battery of memory, language and praxis tasks has been administered to approximately 325 AD patients and 250 controls; the battery clearly distinguishes patients from controls, it has been administered uniformly at 19 widely separated centers, and shows very high retest reliability. By continuing to follow already enrolled subjects with yearly evaluations we propose to determine the sensitivity of the battery to progression of the disease; we will also determine whether baseline neuropsychologic measures predict the time to reach clinical milestones such as institutionalization and other major endpoints. Since subjects already enrolled are predominantly white, middle-class, and well-educated, we will expand the study to determine the reliability and validity of the battery in subjects with less than 9 years of schooling, those in black or Hispanic minority groups and those with coincidental cerebrovascular disease. In conjunction with the newly formed Neuropathology and Neuroimaging Task Forces we will determine whether the semi-quantitative neuropathological findings at autopsy and the neuroimaging abnormalities on MRI correlate with neuropsychologic test scores.